奥氏体不锈钢固溶渗氮研究

对304和904L两种奥氏体不锈钢进行了固溶渗氮研究．用电子探针测定了渗氮层的氮浓度分布，用扫描电子显微镜观察了试样渗层的显微组织，用显微硬度计测量了表面至心部的显微硬度，用X射线衍射仪分析了渗氮层的物相组成，对试样在1mol／L的稀硫酸溶液中的耐蚀性进行了阳极极化曲线分析．结果表明：显微硬度随表面至心部距离的增加而降低．固溶渗氮水冷试样表面的物相为单相奥氏体，炉冷试样的表面物相除高氮奥氏体外，还出现了CrN．渗氮后的试样在1mol／L稀硫酸溶液中的耐蚀性优于未氮化试样．

Study of Solid Solution Nitriding of Austenitic Stainless Steels

Solid solution nitriding of 304 and 904 L austenitic stainless steels in nitrogen atmosphere was investigated. The nitrogen distribution and the nitrided layer microstructure were detected and observed by electron probe microanalyser and scanning electronic microscope. The microhardness from the case to the core was measured by microhardness instrument, and the phase composition of nitration case was analysed by X-ray diffraction. The corrosion resistance of the nitrided sample was studied by anodic polarization curve in the 1 mol/LH2 SO4. The resuits show that the microhardness decreases with increasing of the distance from the case to the core. XRD analytic results indicates that the main phases in the cases of the solution-nitrided samples cooled in the furnace are high nitrogen austenite and CrN phase, and the phase in the cases of the other samples under solid solution nitriding cooled by water are only high nitrogen austenite. The corrosion resisting property of the nitrided sample in the 1 mol/L. H2SO4 is superior to the primitive steels.